Heating element and reflector mounting method



G. HATCH Feb. 4, 1958 2,822,457

HEATING ELEMENT AND REFLECTOR MOUNTING METHOD 2 Sheets-Sheet 1 FiledNOV. 12, 1954 INVENTOR.

GORDON HATCH BY 1, AM

AT TORNEY6 Feb. 4,1958 G. HATCH 2,822,457

7 HEATING ELEMENT AND REFLECTOR MOUNTING METHOD Filed Nov. 12, 1954- 2Sheets5heet 2 INVENTOR. RDON 1 7447-01 5- r mwmwu,

A T TORNEXS' United States Patent ()fiice 2,822,457 Patented F eb. 4,1958 HEATING ELEMENT AND REFLECTOR I MOUNTING METHOD Gordon Hatch,Milwaukee, Wis. Application November 12, 1954, Serial No. 468,322 8 C am (Cl, 219-23 This invention relates to a radiant heating panel. Thepanel is used in various commercial ovens and heating tunnels. It is animprovement upon the panel disclosed in my Patent 2,756,319 granted-July24, 1956, and entitled A Radiant Unit and Oven.

Each panel unit comprises an outer shell. and a tray carrying theheating elements and serving as a reflector. In order to insulate theouter shell more adequately from the heat, the inventioncontemplatesthat the tray which supports the reflector and the heatingelements shall have an insulating box attached to its rear face, thisbox Providing an air space and having mounting blocks or insulationmaterial interposed between its rear wall and the shell, certain of saidblocks having means engaged by anchoring hooks connected with the shellso that'there is no direct metal path of heat conductivity from thereflector to the shell and the thermal-insulation is more efiective thanhas heretofore been deemed possible.

In the drawings:

Fig. 1 is a view in perspective showing a complete panel unit embodyingthe invention.

Fig. 2 is a fragmentary view in longitudinal section on an enlargedscale showing details of the tray mounting.

Fig. 3 is a fragmentary detail view in transverse section.

Fig. 4 is a detail view showing the tray and associated insulatingblocks in bottom perspective.

Fig. 5 is a view of the shell in top perspective.

The shell 6 comprises a sheet metal box having a back wall 7, side walls8 and end walls 9. In practice an electrical conduit may be providedlongitudinally of the back wall 7 as shown at 10, but this is anoptional feature unrelated to the present invention.

At suitable points, the back wall has apertures 11 (Fig. 3) which arecovered by cup shaped mounts 12 having central openings for the hookedmounting bolts 13 hereinafter to be described.

The open-ended tray 15 is provided near each end, and ordinarilytransversely of its intermediate portion, with notched bracket members16 which receive the dielectric spools 17 for supporting the heatingbars 18 as described in the co-pending application above identified. Thetrough shaped reflector 20 lies in the tray 15 and is desirably somewhatconvoluted for better distribution of the radiant heat reflectedthereby.

According to the present invention, the tray 15 is desirably providedalong its back with a box-like projection 21 as best shown in Fig. 2.The margins of walls are flanged and Welded to the back of the tray asindicated at 22. This box-like rearward extension of the tray provides adead-air space therewithin for the improved thermal-insulation of shell7 from the tray 15 and reflector 20. The box-like extension 21 furtherprovides at each end flanged channels 23 which may be weldedtransversely to the rear wall of the tray extension 21 as best shown inFigs. 2 and 4. In each such channel is confined a bar 24 of Marinite orthe like, Marinite being the trademark for a well known asbestoscomposition material.

Desirably there are at least three such transversely extending channelseach confining a bar 24 of the thermal insulating material, three beingsufiicient for panels of seven feet or thereabouts in length. Projectingfrom the respective bars and channels are anchorage means which may takethe form of rods 25 extending successively through all of the transversechannels and bars for substantially the length of the tray. Each suchrod may be provided with a mounting sleeve or grommet 26 protecting itfrom contact with margins of the sheet metal channels where the rodpasses therethrough, reference being made to Fig. 2. I have also shownin Fig. 2 each of the hook bolts 13 engaged over one of the rods 25 inreasonably close proximity to one of the channels 23 and there-enforcing bar 24 of thermal insulation therein contained.

Additional insulating supports are provided by the bars 27, likewisemade of some suitable thermal insulating material such as the asbestoscomposition known as Marinite. These bars 27 are connected by screws orthe like at 28 through the back walls of the channels 23 to thecontained bars 24. Since the screw heads are countersunk in bars 27 in.the manner clearly shown in Figs. 2 and 3 they do not provide any heatconductive path to the shell 7.

Each of the hook bolts 13 is provided with a tension nut 29 disposedwithin one of the cup shaped brackets 12 and accessible through one ofthe openings 11 of the rear wall 7 of the shell 6. By tightening thenuts 29, tension is exerted on the rods 25 to draw the blocks 27 tightlyagainst the rear wall 7 of shell 6 and thereby to hold the tray 15securely fastened within the shell. Because the channels 23 are notdirectly engaged with the tray 15, but are mounted on the rear wall ofthe rearwardly extending box 21, the path for metallic conduction ofheat from the reflector 2t) and the shell 15 is considerably elongatedeven before the heat reaches channels 23. These channels have nometallic contact directly or indirectly with the shell. Direct pressureof the channels is transmitted through the asbestos blocks 27. Tensioniscommunicated through the grommets 26, rods 25, hook bolts 13, and thecup-shaped mounting brackets 12.

Obviously a principal reason for using the heat insulating bars at 24 isto stiffen the channels 23 and to provide non-metallic support for thegrommets 26 and the screws 28. Thus the use of the insulating materialat 24 eliminates several potential lines of metallic heat conductivityand also makes possible the use of relatively lighter metal in thechannels 23.

If desired, lock-nuts 30 may be used on those hook bolts 13 which areaccessible at the end of the unit as shown at the left in Fig. 2. Asshown at the right of Fig. 2, lock-nuts may be omitted from intermediatehook bolts.

The space provided for wiring at the ends of the units may convenientlybe covered, following assembling of the trays and shells, with the coverplates 33.

I claim:

1. In a heating panel of the type employing a reflector tray and ashell, a mounting which comprises a thermalinsulating block connected tothe rear of the tray, a rod extending laterally through the block andproviding anchorage means projecting from such block, and an adjustabletension element connected with the shell and engaged with said anchoragemeans in a position laterally offset from the block and comprising meansfor drawing the tray toward the shell and engaging the insulating blocksunder compression with the shell for supporting the tray therefrom.

2. In a heating panel of the type comprising a shell and a tray-likemounting for heating elements, the combination with said tray-likemounting, of a box connected at the rear thereof and extending towardthe shell, a first set of insulating blocks connected to the rear of thebox, a second set of insulating blocks connected respectively to theblocks of the first set and engaging the shell, anchorage meansprojecting laterally from the blocks of the first set, and tensionelements connecting the anchorage means with the shell and subjecting tocompression the blocks of the second set.

3. In a heating panel of the type which includes an outer shell and atray provided with heating elements, thermal insulating means forconnecting the tray with the shell and including transverse channelmeans connected with the tray and extending rearwardly therefrom,insulating blocks disposed under compression between the respectivechannel means and the shell, and tension elements connecting respectivechannel means with the shell.

4. The device of claim 3 in which the respective channel means areprovided internally with thermal insulating bars substantially fillingand re-enforcing the channel means, and anchorage means for therespective tension elements extending through said bars and projectingfrom said channel means and engaged by said tension elements.

5. The device of claim 3 in which said tray is provided with a box-likerearward extension constituting a dead air space and having a rear wallwith which the respective channel means are connected.

6. In a device of the character described, the combination with a shellhaving side, end and rear walls, of a shallow tray substantiallyspanning the shell between the side walls thereof and comprising heatingelement brackets and heating elements mounted therein, channel meansdisposed transversely of the tray at longitudinal spaced points andconnected with the tray, thermal insulating bars in the respectivechannel means, grommets mounted in said bars, rods extending throughalined grommets of the several bars and projecting from the channelmeans, a second set of thermal insulating bars engaged with the severalchannel means and with rear wall portions of the shell, and hook boltshaving connection with the rods and with the shell and drawing the firstmentioned insulating bars toward the shell whereby to compress thesecond mentioned insulated bars against the shell and thereby toposition said tray and heating elements.

7. The device of claim 6 in which the rear wall portions of the shellhave apertures registering with the hook bolts and provided withcup-shaped mountings disposed within the tray and spanning the aperturesand through which the hook bolts extend, each hook bolt having a nutdisposed within its cup-shaped mounting means and accessible through theshell wall opening spanned by such mounting means.

8. The device of claim 6 in which the tray has a boxlike rearwardextension having a wall portion spaced from the tray and with which therespective channels are connected.

References Cited in the file of this patent UNITED STATES PATENTS1,479,819 Kluever Ian. 8, 1924 1,582,684 Hartwig Apr. 27, 1926 1,686,865Klotz Oct. 9, 1928 1,832,578 Peard Nov. 17, 1931 2,770,704 Razlag Nov.13, 1956

